The state owned oil firm of Venezuela has been imposed with sweeping sanctions by the United States apparently to force the Venezuelan President Nicolas Maduro to accept opposition leader as a the president of the country and step down from his position.

US National Security Adviser John Bolton told reporters at the White House that the sanctions against the Petroleos De Venezuela SA (PDVSA) would cause the company to lose out on $11bn in export revenue and potentially block $7bn in assets of the company.

The imposition of the sanctions means that PDVSA would not be able to collect any cash against the oil exported by it to US customers. Additionally, the assets of the unitsof PDVSA – which includes Citgo, its US-based subsidiary, would be frozen.

This economic sanction imposed on Venezuelan government is the toughest to date and comes at a time when the self-proclaimed interim president and opposition leader Juan Guaido issued a statement claiming that he was taking "orderly control of our republic's assets abroad" so that Maduro can be prevented from trying "to empty the coffers" when he leaves the office.

Last week, a number of countries in South America and the US had acknowledged the leader of the opposition-controlled National Assembly - Guaido, to be the acting president of Venezuela in place of Maduro. The current president of the country, re-elected last May, had been alleged to have rigged the votes amidst a wide boycott of the elections by the opposition.

Maduro however has alleged that the US sanctions essentially is robbing Venezuelans of oil riches which are rightfully their and has termed the US sanctions to be "criminal".

"I have given specific instructions to the head of PDVSA to launch political and legal action, in US and international courts, to defend the property and assets of Citgo," Maduro said on state television. In that speech Maduro said forcefully: "Hands off Venezuela!", directed at the US President Donald Trump in broken English.

The US and other countries have been accused of waging an "economic war" against Venezuela by Mudaro and of trying to remove him from the government.

Venezuela has been in an economic collapse since the dramatic fall of the price of oil globally a few years ago because crude oil makes up a vast portion of the revenues of the country. with inflation rates reaching astronomical figures, millions of Venezuelans had fled the country to seek greener pastures in neighbouring countries.

"We have continued to expose the corruption of Maduro and his cronies, and today's action ensures they can no longer loot the assets of the Venezuelan people," Bolton said at the White House news conference.

Certain transactions and activities with PDVSA have had however been authorised by the US, said Treasury Secretary Steven Mnuchin. It would be possible for Citgo assets in the US to operate if the revenues generated are not transferred to the PDVSA but are directed to an bank account in the US that has been blocked.

The latest sanctions against the Venezuelan oil company were not targeted at the Venezuelan people, said US Secretary of State Mike Pompeo. They sanctions would also not affect any humanitarian assistance which would include medicine and medical devices that were "desperately needed after years of economic destruction under Maduro's rule"m he said.